Domestic Gas Training and Assessment (CCN1)

We offer both Domestic Gas ACS Reassessment and Initial Assessment Training packages.

The package price includes training* and assessment for CCN1 and up to 3** domestic appliances.

*Training may not be mandatory in all cases, please contact us for further advice.

**If you would like to add additional appliances please contact us to discuss your requirements.

Course Info
How to Apply
Package 1: Domestic Gas Reassessment (CCN1)

Reassessment (Renewal)

ACS Reassessment (Renewal) is for operatives looking to renew certificates which have expired in the last 12 months or are due to expire shortly.

These are known as Category 1 candidates who are experienced gas fitters with existing gas knowledge and skills.

In order to undertake the re-assessment/renewal you must provide your current ACS certificate.

This course is run over two intense days to refresh the knowledge of the candidates in core gas and your appliances.*

This is followed by a two day assessment to assess competence in core gas and then a one day assessment for your appliances (max of 3).

If you wish to add an appliance that you do not currently hold, you would need to attend the Initial Appliance training day, this would then be followed by an assessment day.

Course outcome/qualification:

Renew existing certification in order to retain Gas Safe registration.

Pre-requisite knowledge/qualification:

Candidates must supply original documentation as evidence of holding the qualification

Candidates must have an existing ACS CCN1 qualification no more than 12 months from expiry date and meet the requirements of Category 1 outlined below.

If it is longer than 12 months, the assessment will have to be an initial assessment although the training can still be renewal training (two days).

Category 1

Applicants who are experienced gas-fitting operatives who hold ACS, ACoPs, S/NVQ or City & Guilds Gas Qualifications and who is either seeking:

  • Re-assessment on ACS assessment
  • Extension of certification to include additional work range

MOT Certification Process

Candidates undertaking reassessment are eligible for the MOT style certification process. This enables candidates to undertake reassessment up to six months prior to the expiry date of their ‘initial’ ACS certificates.

Package 2: Domestic Gas Initial Assessment (CCN1)

This is not a course for new entrants into the GAS industry.

The ACS training and assessment package is for those who either

  • need to undertake assessment for their core gas (CCN1) and/or appliances, whose ACS expired over 12 months ago*.


  • have recently completed a Managed Learning Programme (MLP) and hold a training certificate, in order to gain ACS accreditation and apply for Gas Safe registration.

*As your certification has expired, the assessments you will undertake will be categorised as INITIAL.

Course outcome/qualification:

Obtain certification in order to apply for Gas Safe registration.

Pre-requisite knowledge/qualification:

Candidates must provide evidence of previous gas qualifications or Managed Learning Programme training certificate.


What Will I Learn?

CCN1 – Core Domestic Natural Gas Safety is a pre-requisite assessment for all other appliance assessments and covers all aspects of gas safety and legislation.


  • Is the Domestic core gas qualification held by gas engineers.
  • It gives a general core knowledge of gas
  • Gas engineers renew this every five years in order to continue working
  • With this qualification, although it installs a broad knowledge, it does not qualify an engineer to work on appliances.
  • They can identify dangers within a property and take appropriate action.
  • They can install gas pipework.

CCN1 Core Domestic Natural Gas Safety Course Content

On completion delegates will be able to establish their safety awareness and competency in the contents of the course listed below:

Safety and safety regulations
Combustion and its control
Flues and ventilation
Pressure and flow
Domestic pipework installation
Tightness testing

Domestic Appliances

In order to work on specific appliances there are various qualifications that can be added onto the core qualification. These are as follows:

  • CENWAT1 – Installation and service of central heating boilers and water heaters
  • CKR1 – Installation and service of cookers
  • HTR1 – Installation and service of gas fires
  • DAH1 – Installation and service of warm air units
  • MET1 – Installation of Gas Meters

The above courses are run concurrently. They take two different forms – Initial or Re-Assessment.

Initial Appliance Training

This training day is for delegates who wish to add a new appliance to their qualifications.

In order to do this you must attend training, and this can be factored into your training schedule.

Candidates are also advised to gain experience in the field beforehand and to document such experience (especially with gas fires).

Example Schedule
MondayTraining and theory (Renewal /Initial)
TuesdayTraining and theory (Renewal /Initial)
WednesdayTheory Day (Initial Only)
ThursdayPractical Assessment (Group A)
FridayPractical Assessment (Group B)
MondayAppliance Assessment Day (Group A) or Initial Appliance Training Day*
TuesdayAppliance Assessment Day (Group B) or Initial Appliance Assessment

If you wish to add an appliance that you do not currently hold, you would need to attend the Initial Appliance training day, which would then be followed by an additional assessment day.


Fee Breakdown

Training and Theory: £430
Theory Day (Initial Assessment Only) £195
Practical Assessment: £315
Appliance Assessment: £135 for up to three appliances
Additional appliances: £135 each
Training Manual: £53
Certification: £48

*****Discounts apply for group bookings – call now!*****
Domestic Gas Training and Assessment (CCN1)
Course Outline: pre-requisite assessment for all other appliance assessments and covers all aspects of gas safety and legislation.
DurationWe can adapt this course to suit your requirements
Campus / Adult Skills CentreColchester Campus
Start DateNext available dates:
Training and Theory: 17th and 18th June 2024
Practical Assessment: 19th, 20th or 21st June 2024
Appliance Assessment: 24th, 25th and 26th June 2024
PriceReassessment: £981
Initial Assessment: £1,176


All fees, prices and funding information shown on this page are for courses starting in the 2023-24 academic year unless stated otherwise, and are correct at the time of entering/printing information, however these may be subject to change due to factors outside of our control. The College cannot accept legal or financial liability as a result of any such changes.

Courses fees are generally not confirmed for September until June / July due to the above factors.

The course information describes programmes offered by Colchester Institute. The College takes all reasonable steps to provide courses as described, but cannot guarantee provision. The information is for guidance and does not form any part of a contract.

The College reserves the right to update and amend information as and when necessary. Colchester Institute will do its best to provide the courses shown, but may have to modify or withdraw a course depending on customer demand and other factors.